The Arc Flash Hazard report shows upstream devices that do not exist on the one-line

There are two ways this can happen:

• Bus Data has user-defined trip times.
• Bus Data has pre-defined fixed times. The trip times specified in the library are used. Based on the voltage of the faulted bus, you could see the following in the column Upstream Trip Device Function:

Pre-defined Trip Times

LV Bus	MV Bus
INST	50
ST-MIN	51-MIN
ST-INT	51-INT
ST-MAX	51-MAX

Next: Determination of System Grounding

More Information

• Arc Flash Hazard Analysis
• Troubleshooting Arc Flash Hazard Results